Monitoring cameras are installed in various places today. Monitoring cameras are installed both indoor and outdoor as well as on permanent and temporary installations. Depending on where a monitoring camera is installed and depending on the conditions under it is to be operated, there will be a very large variation with regard to the image processing capabilities that are required of the camera. For example, monitoring of a location in which during daytime images of a large number of passing objects are to be processed requires much image processing power. This contrasts to a situation where the same location is monitored during night time when no objects are passing in the field of view of the camera. Moreover, due to the fact that image detectors/sensors become more and more refined, and deliver ever increasing flows of image data, the requirements on the processing power of monitoring cameras will continue to increase. Such an increased need for processing power will typically be associated with increased electric power consumption in the camera.
Power consumption is always an issue in all electronic products including monitoring cameras. There are several reasons for that, such as environmental reasons but there are also other reasons. One such reason could be when a large number of cameras are installed on a temporary basis, e.g. monitoring a sports event. In this case it could be costly to make a proper installation of electrical power from the power grid. One solution to this problem would be to use Power over Ethernet, PoE, which has a limited maximum power output. Another example of when the power consumption would be an issue could also be because the heat the image processing circuitry create cannot be taken care of and, as a consequence, the processing circuitry cannot be used the way it is needed to process the image.
In other words, there are several scenarios where the power supplied to the monitoring camera will be insufficient to handle all processing requirements in the monitoring camera.
For example, with regard to the example of PoE, there are different classes of PoE and in some situations the monitoring camera has too low class to be able to deal with what is happening in the scene monitored by the monitoring camera. For example, having the monitoring camera at home a lot of the times nothing happens, and a low class of PoE is may be used. However, when something happens you want to be able to use a high amount of effect, which you probably will not have with a low class of PoE.
WO 94/03014 A1 describes a low power video security monitoring system. When motion is detected by a video camera the system establishes a connection with a video monitoring facility and transmits compressed video images to the facility.
EP 2177970 A1 describes power management in an electronic device. The device comprises a flash unit and a camera. A battery level is measured before a decision is made whether or not to utilize the flash when taking a photograph.